Just saying your question is not a homework or other textbook-style exercise may not be enough. I recommend saying why you are asking the question. Letting others in on your motive can help people give a more appropriate answer -- i.e. at the proper level, giving/withholding the right amount of help, or pointing you to a suitable reference.

Note that the HW forum is for homework and textbook-like questions. Generally, even if it is not meant for a homework assignment, if someone is asking those types of questions, they will get the same benefit of it being treated like a HW question as those who are actually doing it for HW.